1. Field of the Invention
The present invention relates to a gas filling and dispensing device and to a filling method.
The invention relates more particularly to a gas filling and dispensing device comprising a body to be placed in the opening of a pressurized gas storage container, a gas withdrawal circuit extending between an upstream first end intended to be connected to the inside of the container and a downstream second end intended to be connected to a gas user, a filling duct having an upstream first end intended to be connected to the inside of the container and a downstream second end intended to be connected to a filling member, the filling duct including at least one portion separate from the withdrawal circuit, said filling duct including a first valve.
2. Related Art
To fill gas cylinders to high pressure (especially in applications for supplying a gaseous fuel such as hydrogen), it is possible to use quick-fit connection systems for coupling a filling connector (that delivers pressurized gas to the cylinder) to the filling port of a tap (or the like) mounted in the opening of the cylinder. To do this, at the start of the operation, the filling connector is firstly coupled before being pressurized (that is to say it does not deliver gas before it is connected to the filling port).
The filling valve is preferably (without this being limiting) a nonreturn valve which closes automatically and opens under the action of the gas delivered via the filling connector.
In the event of the filling valve failing or sealing imperfectly, there is a risk of the pressure rising in the connection chamber of the filling port.
This abnormally high pressure may damage the filling port, the filling connector which is connected thereto (extrusion of the seals and loss of sealing) and also the withdrawal connector when withdrawal and filling operations are carried out via a common port (a single connection).
To solve this problem, safety valves (pressure-relief devices or PRDs) are used. However, in certain applications (in particular for dangerous or inflammable gases), these safety valves risk releasing into the atmosphere dangerous amounts of gas (clouds or uncontrolled flames).
Another solution consists in completely decoupling the filling circuit from the withdrawal circuit so as to prevent the high gas pressure of the defective filling circuit from reaching the withdrawal circuit. This does not completely solve the problem of the risk of the pressure rising in the filling port and means that the possibility of having common and coincident filling and withdrawal ports is lost.